I worked on this game with 2 artists at a Game Jam this past weekend. I was the only programmer so I used C2.
The theme was "powers combined"... so we tried to make a 2Player shooter that you'd combine bullets to make a Power Blast to take out Boss targets. Its decent for 2 days of work...
I made a 1-player-mode but the other Guardian doesn't move, he/she just shoots..(ran out of time!)